Storage system and communication bandwidth control method

Abstract

An object of the present invention is to efficiently perform load balancing between Fibre Channel switches and storage apparatuses, avoiding communication congestion, and maintaining high system performance. The present invention provides a method for controlling a communication bandwidth between a network switch having a plurality of ports for forming a network, and a storage apparatus having ports respectively connected to at least two of the ports, the method including: transferring one or more data frames to the storage apparatus via a first port of the network switch connected to the storage apparatus; determining whether or not an overflow has occurred in a first buffer memory associated with the first port during the transfer of the one or more data frames; identifying, if an overflow has occurred in the first buffer memory, a second port of the network switch connected to the storage apparatus; and transferring the one or more data frames to the storage apparatus via the first port and the second port.

1 . A method for controlling a communication bandwidth between a network switch having a plurality of ports for forming a first network, and a storage apparatus having ports respectively connected to at least two of the ports, the method comprising:
 transferring one or more data frames to the storage apparatus via a first port of the network switch connected to the storage apparatus;   determining whether or not an overflow has occurred in a first buffer memory associated with the first port during the transfer of the one or more data frames;   identifying, if an overflow has occurred in the first buffer memory, a second port of the network switch connected to the storage apparatus; and   transferring the one or more data frames to the storage apparatus via the first port and the second port.   
   
   
       2 . The control method according to  claim 1 , wherein:
 the network switch has a channel management table that manages channel information relating to the plurality of ports; and   the identification of the second port includes identifying another port connected to the storage apparatus the first port is connected to, by referring to the channel management table.   
   
   
       3 . The control method according to  claim 2 , wherein the channel management table includes the correspondence between the at least two ports, the storage apparatus as a node connected to the at least two ports, and the ports of the node. 
   
   
       4 . The control method according to  claim 1 , further comprising sending the storage apparatus a permission request for data frame transfer via the identified second port. 
   
   
       5 . The control method according to  claim 4 , wherein the sending includes sending the permission request via the second network connecting the network switch and the storage apparatus. 
   
   
       6 . The control method according to  claim 4 , further comprising the storage apparatus sending a response indicating that permission is granted, to the network switch in response to the permission request. 
   
   
       7 . The control method according to  claim 1 , further comprising: checking the order of the one or more data frames transferred to the storage apparatus via the first port and the second port; and re-arranging the order of the one or more data frames based on the result. 
   
   
       8 . The control method according to  claim 7 , further comprising sending the rearranged one or more data frames to a target device indicated by the one or more data frames. 
   
   
       9 . A method for controlling a communication bandwidth between a network switch having a plurality of ports for forming a first network, and a storage apparatus having ports respectively connected to at least two of the ports, the method comprising:
 reading data from one or more disk devices in the storage apparatus and converting the data into one or more data frames;   transferring the one or more data frames to the network switch via a first port of the storage apparatus connected to the network switch;   determining whether or not an overflow has occurred in first buffer memory associated with the first port during the data frame transfer;   identifying, if an overflow has occurred in the first buffer memory, a second port of the network switch connected to the storage apparatus; and   transferring the one or more data frames to the network switch via the first port and the second port.   
   
   
       10 . The control method according to  claim 9 , wherein the identification of the second port includes inquiring of the network switch whether another port connected to the network switch connected to the first port exists or not. 
   
   
       11 . The control method according to  claim 10 , wherein the network switch has a channel management table managing channel information relating to the plurality of ports, and, referring to the channel management table, identifies, as a second port, the other port connected to the network switch the first port is connected to. 
   
   
       12 . The control method according to  claim 10 , wherein the inquiry includes the storage apparatus making an inquiry to the network switch via a second network. 
   
   
       13 . A storage system including a network switch and a storage apparatus connected via a first network, the network switch comprising:
 a plurality of ports having buffer memories for forming the first network;   a channel management table that manages channel information about the plurality of ports;   an overflow detection unit that detects the occurrence of any overflow in the buffer memories of the plurality of ports;   a port identification unit that, upon detection of an overflow, identifies, as a second port, another port connected to a node the first port with the buffer memory with the overflow is connected to, by referring to the channel management table;   a control unit that controls one or more paths for the one or more data frames so that the one or more data frames are transferred using the second port as well as the first port.   
   
   
       14 . The storage system according to  claim 13 , further comprising: a communication unit that sends the storage apparatus a permission request for data frame transfer using the identified second port. 
   
   
       15 . The storage system according to  claim 14 , wherein the communication unit sends the permission request via the second network. 
   
   
       16 . The storage system according to  claim 14 , wherein the storage system sends a response indicating that permission is granted, to the network switch in response to the permission request. 
   
   
       17 . The storage system according to  claim 13 , wherein the storage system checks the order of the one or more data frames transferred from the first port and the second port, and based on the result, re-arranges the order of the data frames.